Exploration of supramolecular assemblies of rac-1,3-cyclohexanedicarboxylic acid

Abstract

Abstract Supramolecular assemblies of rac-1,3-cyclohexanedicarboxylic acid (1) with melamine (a), 1,2-bis(4-pyridyl)ethene (b); 1, 2-bis(4pyridyl)ethane (c) in the presence of Co(II), and 1,10-phenanthroline (d) along with Cu(II) and Ni(II), respectively 1a - 1d and 1d', have been reported. All the assemblies were prepared by crystallization method, through slow-evaporation process, at ambient conditions. All the complexes yield sheet structures that are stacked in three-dimensional arrangement, however, each structure is unique within three-dimensional networks with varied arrangements of either organic entities or coordinated ensembles. For instance, while a host-guest type assembly was observed in 1a, only crinkled tapes are observed in 1b. Among coordination complexes, 1c has an interpenetrated cubic network, whereas 1d and 1d' form host-guest networks. A noteworthy feature to highlight is that the water molecules in the channels of 1d organize in the form of pentamers, which are further held together through tetrameric network, with the aid of hydrogen bonds. A further interesting feature is the presence of acid 1 in different conformations in the complexes as cis form in 1b, 1c and 1d and trans form in 1d'. However, in 1a both cis and trans conformers are observed. � 2015 Elsevier B.V.